My Vote would be Firefoz, heck im even using it now posting this reply.
Anyway people have to remeber that Firefox is Free thus it is Supseptible to Human Errors and Bugs, and thought its free they dont have to update it but they choose too because because they made it great. Plus its updated as long as your connected to the internet, and have the appropriate Firewal/Anti-Virus-Spyware programs running and some addons too boot ive havent had a reason to run IE except logging into certain sites that require IE and Download Firefox. Use the Firefox browser is better features than IE, being developed all the time so its always getting better than IE. One day i hope Firefox will be Avaliable to all Platforms and come bundled with every OS on install, of course that wont happen...